Slacklining is a little harder than riding a bike - at least that's what Edward Yates says.

During the RiverRocks finale Saturday, Yates and Jimmy Schwartz demonstrated slacklining - the practice of walking across a one-inch strip of nylon webbing between two points, derived in part from tightrope walking - underneath the Walnut Street Bridge.

Crowds gathered as the two balanced in the air just below the bridge's surface - but not over the Tennessee River - walking about 30 feet between two of the ground supports.

"Hopefully, this being out in the public will inspire people to get out and try it," Schwartz said.

For organizers of RiverRocks, the 10-day event that celebrates Chattanooga's natural resources, that is the point of the entire festival.

"Our goal is to try and get a bunch of people outside," said Claudia Moore, director of marketing for RiverRocks.

In its third year, the festival featured new events, including the popular Over the Edge, where 78 participants rappelled the 20-story SunTrust building, and the Gig City Entertainment concert, where the speed of Chattanooga's 1-gigabit-per-second Internet was demonstrated by streaming musicians live from around the world.

In addition, RiverRocks also increased the number of events surrounding the finale this year in hopes of attracting more people to the festival, Moore said.

"Last year, we had 40,000 or so attend, and I am going to be real surprised if we don't exceed that this year," Moore said.

The finale also included zipline rides, an obstacle course for kids and nature demonstrations from the Chattanooga Arboretum and Nature Center.

At the nature demonstrations, a hedgehog wobbled around the ground under a tent as kids crowded around to get a better view but were advised not to touch the animal.

"To me, an important part about being outside is learning about the environment around you," said Corey Hagen, director of education at the Nature Center.

The center also offered talks on local birds, snakes and the Native American history and culture of the region.